# How do you solve \frac { 16} { 4} = \frac { 12} { x }?

Jul 4, 2017

$x = 3$

#### Explanation:

1. Cross multiply.

Multiply the numerator of the first fraction by the denominator of the second fraction, and set that equal to the numerator of the second fraction times the denominator of the first fraction. For example:

$\frac{a}{b} = \frac{c}{d}$

$a d = b c$

$\frac{16}{4} = \frac{12}{x}$

$16 x = 12 \left(4\right)$

$16 x = 48$

2. Divide both sides by 16 to find x.

$\frac{\cancel{16} x}{\cancel{16}} = \frac{48}{16}$

$x = 3$